This invention relates generally to the field of multiple pane insulating windows or glazing panels and, in particular relates to an improved corner connector piece for joining adjacent spacer tubes which are used to separate the panes of a multiple pane glazing panel.
It is very well known in the art to provide windows having multiple panes of glass, the panes being separated by an insulating air space. It is common practice to separate the panes of glass by means of a perimeter frame comprising sections of spacer tubing joined together at adjacent ends and disposed between the panes in sealed relation thereto. The tubes commonly contain a desiccant which serves to absorb moisture from the air which is trapped within the space between the window panes.
The prior art has provided various forms of corner pieces for use in connecting together the tubes of the spacer assembly. One such arrangement is illustrated in our U.S. Pat. No. 4,296,587 issued Oct. 27th, 1981. This patent illustrates a rigid corner piece having a pair of arms arranged at right angles to one another with each arm being adapted to enter into and engage within an end portion of a respective spacer tube. In order to provide firm engagement between the corner piece and the spacer tubes, the corner piece is provided with teeth which engage with serrations formed on interior walls of the respective spacer tubes. The corner piece is designed to substantially fully block the end of the spacer tube when inserted thereby to prevent falling out of the desiccant material during assembly.
Although the above-noted rigid corner piece arrangement has been found to perform very well, it has been found desirable, in many instances, to move away from the rigid corner piece arrangement previously used and to provide a corner piece which can be flexed or pivoted such that the arms of the corner piece can move from a generally straight line relationship relative to one another into a generally right angle relationship with one another. A corner connector of this type enables the individual spacer tubes to be arranged in a linear relationship during the initial spacer frame assembly process. The corner connectors, in an open position, are inserted into each adjacent end of the aligned spacer tubes. Following this procedure, the complete frame comprising four spacer tubes and four corner pieces is then squared up into the desired rectangular shape with the corner pieces being arranged to hold the desired rectangular shape plus allowing the spacer frame to be positioned between an adjacent pair of glazing panels for the purpose described previously.
The prior art has provided several forms of flexible corner pieces for use in the above-described manner. These corner pieces generally comprise a pair of arms which are arranged to enter into and engage within an end portion of a respective spacer tube. These arms are joined together by a flexible portion which enables the arms to be pivoted into a generally right angle relationship with each other. In order to secure the arms in the right angle relationship, the prior art structures employ interengaging portions which may be snap-fitted together to hold the arms of the corner piece in the desired right angle relationship. An example of such snap-fitting portions comprises an arrow-shaped male member which fits into a correspondingly shaped female opening. Various other interlocking shapes and configurations have also been provided. Although these arrangements are, generally speaking, operable, they have disadvantages in that the interlocking shapes are relatively complex thus requiring the use of relatively complex molding equipment and processes. Many of these designs also have recesses or openings therein which allow some of the mastic sealing compound which is employed to effect a seal between the spacer and the glazing panels to escape thus increasing the possibility of air/moisture leakage into the space between the glazing panels.